Surgical procedures requiring cutting of tissue can result in bleeding at the site of the cutting. Various techniques have been adapted to control bleeding with varying degrees of success such as, for example, suturing, applying clips to blood vessels, and using surgical fasteners, as well as electrocautery and other tissue heating techniques.
Surgical devices using surgical fasteners entail grasping or clamping tissue between opposing jaw structure and then joining the tissue by employing the surgical fasteners. These devices are well known in the art. In some instruments a knife is provided to cut the tissue which has been joined by the fasteners. The fasteners are typically in the form of surgical staples however, two part polymeric fasteners are also utilized.
Instruments for this purpose can comprise two elongated members which are respectively used to capture or clamp tissue. Typically, one of the members carries a cartridge which houses a plurality of staples arranged in at least two lateral rows while the other member comprises an anvil which defines a surface for forming the staple legs as the fasteners are driven from the cartridge. Where two part fasteners are used, this member carries the mating part, e.g. the receiver, to the fasteners driven from the cartridge. Generally, the stapling operation is effected by a pusher which travels longitudinally through the cartridge carrying member, with the pusher acting upon the staples to sequentially eject them from the cartridge. A knife may travel with the pusher between the staple rows to longitudinally cut and/or open the stapled tissue between the rows of staples. Such instruments are disclosed in U.S. Pat. Nos. 3,079,606 and 3,490,675.
A later stapler disclosed in U.S. Pat. No. 3,499,591 applies a double row of staples on each side of the incision. This is accomplished by providing a cartridge assembly in which a cam member moves through an elongate guide path between two sets of staggered staple carrying grooves. Staple drive members are located within the grooves and are positioned in such a manner so as to be contacted by the longitudinally moving cam to effect ejection of the staples. Other examples of staplers are disclosed in U.S. Pat. Nos. 4,429,695, 5,065,929, and 5,156,614.
Electrocautery devices are preferred in certain surgical procedures for effecting improved hemostasis by heating tissue and blood vessels using thermogenic energy, preferably radiofrequency energy, to cause coagulation or cauterization. Monopolar devices utilize one electrode associated with a cutting or cauterizing instrument and a remote return electrode, usually adhered externally to the patient. Bipolar instruments utilize two electrodes and the cauterizing current is generally limited to tissue between the two electrodes of a tissue treating portion (e.g., end effector) of an instrument.
It would be desirable to have electrosurgical stapling devices combining the structural and functional aspects of stapling instruments and electrocautery devices to provide improved hemostasis by using thermogenic energy to cause coagulation or cauterization and surgical fasteners to staple the tissue, either before, during or after the use of thermogenic energy.
Therefore, it is an aspect of the invention to provide an electrosurgical stapling apparatus which uses thermogenic energy and staples for providing hemostasis, tissue joining or welding, and also strengthens tissue in proximity to a staple line and provides hemostasis along the staple line to reduce or prevent staple line bleeding.